Ultrasound Vector Flow Imaging in a Finger Artery Phantom

A 0.8-mm diameter silicone artery phantom, exhibiting mechanical properties comparable to those of digital arteries, was subjected to pulsatile flow generated by a custom-built pump replicating the systolic–diastolic waveform previously measured in the index finger digital artery using an ultrasound scanner (VisualSonics VevoMD). The circulating fluid (CIRS Doppler Fluid, model 769DF) reproduced the acoustic and physical properties of human blood, thereby providing appropriate conditions for the evaluation of Doppler ultrasound techniques.

A sequence of three plane waves tilted at –5°, 5°, and 7° was implemented using the VADA module of the VisualSonics Vevo F2 system equipped with the UHF71x linear array probe (71–30 MHz). A least-squares multi-angle Doppler estimator for plane-wave vector flow imaging was subsequently developed in MATLAB. The resulting vector velocity fields were overlaid on B-mode images as a function of time. In addition, the velocity magnitude was extracted at a predefined location and plotted over time. The final video was recorded at a temporal resolution of 10 frames per second for enhanced visualisation.